DESC:FIELD OF THE INVENTION
The present invention relates to a fungicidal composition. More particularly, the invention relates to a synergistic fungicidal mixture comprising Thifluzamide, Difenoconazole and Validamycin.
BACKGROUND OF THE INVENTION
The prevention of plant diseases caused by fungal plant pathogens is of utmost importance in enhancing crop efficiency. Damage to crops by fungal pathogens can cause significant drop in crop-yields and thereby result in food shortages and rise in prices of essential commodities. Although many fungicides are commercially available for controlling fungal pathogens, there is a continued need for newer mixtures and compositions that are more effective, less expensive, safer for humans and the environment, and have novel molecular modes of action.
Rice (Oryza sativa), wheat (Triticum aestivum) and maize (Zea mays) are the three leading food crops in the world; together they directly supply more than 50% of all calories consumed by the entire human population. Rice provides 21% of global human per capita energy and 15% of per capita protein. Although rice protein ranks high in nutritional quality among cereals, protein content is modest. Rice also provides minerals, vitamins, and fibre, although all constituents except carbohydrates are reduced by milling. The crop failure, for any reason, poses a real threat of starvation. Rice is commonly effected by Blast (Magnaporthe oryzae), Bacterial Leaf Blight (Xanthomonas oryzae pv.oryzae), Brown Spot (Helminthosporium oryzae), Sheath Rot (Sarocladium oryzae), Sheath Blight (Rhizoctonia Solani), False Smut (Ustilaginoidea virens), Grain discolouration (fungal complex), Leaf streak (Xanthomonas oryzae pv. oryzicola) etc. Rice blast, caused by a fungus Magnaporthe oryzae is by far the most important disease of the diseases that attack rice resulting in a grain loss to the tune of 70-80%. Magnaporthe oryzae causes formation of lesions on the leaves, stems, peduncles, panicles, seeds and even roots. So great is the potential threat for crop failure from this disease that it has been ranked among the most important plant diseases of them all. The rice blast fungus is found wherever rice is grown and is a major threat. Each year the fungus is estimated to destroy enough rice that can feed more than 60 million people. Failures of entire rice crops have resulted directly from rice blast epidemics. There is a need for more effective agents for protecting plants, including rice, from damage caused by this pathogen. Number of measures including chemical, organic etc. are recommended for its control among which the chemical methods (fungicides) are best suited considering low economic costs and easy application methods. Fungicides are compounds, of natural or synthetic origin, which act to protect plants against damage caused by fungi. Current methods of agriculture rely heavily on the use of fungicides. In fact, some crops cannot be grown usefully without the use of fungicides. The use of fungicides allows a grower to increase the yield and the quality of the crop and consequently increase the value of the crop. In most situations the increase in value of the crop is worth at least three times the cost of the use of the fungicides.
Unfortunately, no one fungicide is useful in all situations and repeated usage of a single fungicide frequently leads to the development of resistance. Consequently, research is being conducted to produce fungicides and combinations of fungicides that are safer, that have better performance, that require lower dosages, that are easier to use, and that are less expensive. Combinations of fungicides are often used to improve disease control and to prevent development of resistant fungal strains. It is desirable to target a plurality of fungal pathogens and enhance the efficacy of disease control by using mixtures of fungicides that provide a combination of curative, systemic and preventive control of fungal pathogens. Also desirable are mixtures that exhibit greater residual period to allow for elongated spray intervals. It is also desirable to combine fungicides that inhibit different biological pathways in the fungal pathogens to prevent development of resistance to any one particular fungicide.
It is always desirable to reduce the quantity of fungicides used while ensuring effective protection of crops from diseases caused by fungal pathogens. Combinations of fungicides may provide significantly enhanced disease control against fungal pathogens than would be possible based on the activity of the individual fungicide. This synergism has been described as "the cooperative action of two components of a mixture, such that the total effect is greater or more prolonged than the sum of the effects of the two (or more) taken independently" (Reference: P. M. L. Tames, Meth. J. Plant Pathology 1964, 70, 73-80). Hence there is a continued need for new fungicidal combinations that are useful in achieving one or more of the preceding objectives.
Formulating a fungicidal composition which prevents development of resistant fungal strains, and is also safer for humans and the environment is extremely difficult. Thus, it is an objective of this invention to provide a synergistic fungicidal combination which demonstrates an enhanced anti-fungal effect along with reduced cost and minimal environmental damage. Accordingly, the present invention provides a synergistic fungicidal combination comprising (a) Thifluzamide; and (b) Difenoconazole and agriculturally suitable salts thereof; and optionally (c) Validamycin and agriculturally suitable salts thereof.
In view of the above, obtaining a fungicidal composition which demonstrates no cross-resistance to existing fungicidal agents, no toxicity problems and negligible impact on the environment is extremely difficult.
Thifluzamide (IUPAC name: 2',6'-dibromo-2-methyl-4'-trifluoromethoxy-4-trifluoromethyl-1,3-thiazole-5-carboxanilide, Molecular formula: C13H6Br2F6N2O2S, Molecular weight: 528.1) is a fungicide which is generally used to control Basidiomycetes. It inhibits the respiratory electron transport chain by disrupting complex II (succinate dehydrogenase).
When Thifluzamide is applied as foliar spray or soil drench, it is rapidly absorbed by the roots and leaves and translocated to xylem and apoplast throughout the plant. Thifluzamide is a compound that has high pesticidal activity against leaf spot withering disease. As the fungicidal agent, to treat rice leaf spot withering disease in rice plant cultivation, is applied when there is less water in the paddy fields, dissolution/diffusion rates of the effective ingredient can have a significant effect on efficacy. Since Thifluzamide is sparingly soluble in water, about 1.6 mg/L (20 °C.), there is a need to develop a method that enhances its dispersion in water and improves its uptake.
Difenoconazole (IUPAC name: cis,trans-3-chloro-4-[(2RS,4RS;2RS,4SR)-4-methyl-2-(1H-1,2,4-triazol-1-ylmethyl)-1,3-dioxolan-2-yl]phenyl-4-chlorophenyl ether, Molecular formula: C19H17Cl2N3O3, Molecular weight: 406.3) was introduced in the year 1989. Difenoconazole is a curative and protective systemic fungicide which inhibits cell membrane ergosterol biosynthesis (sterol demethylation inhibitor). Ergosterol is a component of yeast and other fungal cell membranes, serving many of the same functions that cholesterol serves in animal cells. As many fungi and protozoa cannot survive without ergosterol, the enzymes that create it have become important targets for drug discovery.
Difenoconazole controls many fungi, particularly Ascomycetes, Basidiomycetes and Deuteromycete,s including Alternaria, Ascochyta, Cercospora, Cercosporidium, Colletotrichum, Guignardia, Mycosphaerella, Phoma, Ramularia, Rhizoctonia, Septoria, Uncinula, Venturia spp., Erysiphaceae, Uredinales and several seed-borne pathogens. It is used against disease complexes in grapes, pome fruit, stone fruit, potatoes, sugar beet, oilseed rape, banana, cereals, rice, soya beans, ornamentals and various vegetable crops. It is also used as a seed treatment against a range of pathogens in wheat and barley.
Validamycin (IUPAC name: (1R,2R,3S,4S,6R)-2,3-dihydroxy-6-hydroxymethyl-4-[(1S,4R,5S,6S)-4,5,6-trihydroxy-3-hydroxymethylcyclohex-2-enylamino]cyclohexyl-??-D-glucopyranoside, Molecular formula: C20H35NO13, Molecular weight: 497.5) was reported to be an antibiotic by T. Iwasa et al. in J. Antibot., 1970, 23, 595 and was introduced in the year 1972. Validamycin is a non-systemic antibiotic with a fungistatic action. It causes abnormal branching of the tips of the pathogen, followed by cessation of further development. It inhibits trehalase, an enzyme which mediates the digestion of the carbohydrate trehalose and transport of glucose to the hyphal’s tips.
Validamycin controls the fungus Rhizoctonia solani in rice, potatoes, vegetables, strawberries, tobacco, ginger and other crops, sheath blight of paddy and wheat, false smut of paddy, black smut of wheat, leaf blight of corn, scab of apple and pear, ring rot of apple and pear, powdery mildew, Fusarium wilt and early blight of vegetables, damping-off diseases of cotton, rice and sugar beet etc.
It was observed that using the combination formulation comprising Thifluzamide, Difenoconazole and Validamycin in the ranges in accordance with the present invention leads to much better percentile control of the different fungal diseases like blast, blight, spot, rot, smut and wilt etc. in comparison to the individual commercial formulations. Therefore, it will control almost all major fungal diseases in cereals, fruits and vegetables. Apart from this, it will have antibiotic action that arises from Validamycin. Reduced volumes of spray in comparison to individual commercial formulations are required and this considerably reduces the spray of individual active ingredients in the combination formulations. Lower grams per hectare of the active ingredients are sprayed than the individual commercial formulations. Consequently, the residual amount of fungicides in the crops is also much lower, which reduces the environmental load along with occupational hazard to the applicators considerably. Thus, the toxic effects of the residues of the active ingredients on the biotic and abiotic part of the ecosystem are minimized.
Thus, it is an object of the present invention to provide a novel fungicidal composition which demonstrates a high controlling effect of fungi along with reduced crop production cost and reduced environmental load. Accordingly, the present invention provides a synergistic fungicidal mixture comprising Thifluzamide, Difenoconazole and Validamycin.
SUMMARY OF THE INVENTION
In accordance with an embodiment of the invention, there is provided a synergistic fungicidal composition, comprising Thifluzamide, Difenoconazole, Validamycin, and additives.
The synergistic fungicidal composition comprises Thifluzamide, Difenoconazole, and Validamycin in ratios ranging from 1.33-3.33:1.33-2.67:1, and preferably in a ratio of 3:2:1.
Said composition, comprises Thifluzamide in an amount of 4 to 10%, Difenoconazole in an amount of 4 to 8% and Validamycin in an amount of 3%.
Further, the synergistic fungicidal composition, may be formulated as a wettable powder (WP), a suspension concentrate (SC), soluble liquid (SL) or water dispersible granules (WG).
Still further, the synergistic fungicidal composition, comprises additives selected from the group consisting of anti-freezing agent, dispersing cum wetting agent, defoamer, biocide, thickener, water and combinations thereof, and the composition is in the form of a suspension concentrate (SC).
The synergistic fungicidal composition, contains: an anti-freezing agent in an amount of 1.00 to 8.00%, preferably 5%, a dispersing cum wetting agent in an amount of 2.00 to 10.00%, preferably 5%, a defoamer or anti-foaming agent in an amount of 0.01 to 0.50%, preferably 0.20%, a biocide in an amount of 0.01 to 0.50%, preferably 0.20%, and a thickener in an amount of 0.10-0.50%, preferably 0.25%.
In accordance with another embodiment of the invention, the synergistic fungicidal composition is non-phytotoxic.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1. is a flowchart for preparing a synergistic fungicidal composition in the form of a suspension concentrate (SC).
DETAILED DESCRIPTION OF THE INVENTION
Discussed below are some representative embodiments of the present invention. The invention in its broader aspects is not limited to the specific details and representative methods. The illustrative examples are described in this section in connection with the embodiments and methods provided. The invention according to its various aspects is particularly pointed out and distinctly claimed in the appended claims read in view of this specification and appropriate equivalents.
It is to be noted that, as used in the specification and the appended claims, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a composition containing “a compound” includes a mixture of two or more compounds. It should also be noted that the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.
The expression of various quantities in terms of “% w/w” or “%” means the percentage by weight, relative to the weight of the total solution or composition unless otherwise specified.
The term "agrochemically effective amount" is that quantity of active agent, applied in any amount which will provide the required control of fungal pathogens and diseases. The particular amount is dependent upon many factors including, for example, the crop, type of fungus and disease sought to be controlled and environmental conditions. The selection of the proper quantity of active agent to be applied, however, is within the expertise of one skilled in the art. Further, the term “active ingredient” (A.I.) or “active agent” used herein refers to that component of the composition responsible for control of fungus or fungal disease.
As used herein, the expressions “WP formulation”, “SL formulation”, “SC formulation” and “WG formulation” are the international denominations adopted by the FAO (Food and Agricultural Organization of the United Nations) to designate “wettable powder”, “soluble liquid”, “aqueous suspension concentrate” and “water dispersible granules” respectively.
Compositions comprising a single fungicidally active component suffer from numerous drawbacks such as development of resistant fungal species, requirement of high amount and concentration of the active ingredient, environmental damage, seepage of the active component into ground water, phyto-toxicity and harmful effects on the health of animals and humans.
Accordingly, the inventors of the present invention have developed a synergistic fungicidal composition comprising Thifluzamide, Difenoconazole; and Validamycin, wherein the mass ratio between Thifluzamide, Difenoconazole, and Validamycin ranges from 1.33-3.33:1.33-2.67:1, and is preferably 3:2:1. Preferably, the fungicidal composition contains Thifluzamide in an amount of 4 to 10%, Difenoconazole in an amount of 4 to 8% and Validamycin in an amount of 3%.
The synergistic fungicidal composition, further comprises additives selected from the group consisting of anti-freezing agent, dispersing cum wetting agent, defoamer, biocide, thickener, water and combinations thereof, and the composition is in the form of a suspension concentrate (SC). The term “suspension concentrate” used herein refers to a suspension of the active fungicide and excipients in a small quantity of liquid, usually water. A composition in the form of a suspension concentrate is user friendly and affords a reduced risk of occupational exposure.
An anti-freezing agent is generally added to fungicidal compositions, to prevent the aqueous compositions from freezing. Suitable anti-freezing agents useful herein, but not limited to, include propylene glycol, Diethylene glycol (DEG), Mono ethylene glycol (MEG) and combinations thereof. The anti-freezing agent is present in an amount in the range from 1.00-8.00%, preferably 5%.
A dispersing cum wetting agent is another important component of a suspension concentrates as it facilitates the formation of a suspension of a water insoluble substrate in water. Non-limiting examples of dispersing cum wetting agents that can be used in the present invention include non-ionic surfactants and amine salt of phosphate tristyryl phenol ethylated, acrylic copolymer, ethoxylated polyarylphenol phosphate ester, each of which can be used individually or in combination, in an amount in the range from 2.00-10.00%, preferably 5%.
A defoamer, also called as anti-foaming agent, is generally added to a fungicidal composition as foam formation prevents the efficient filling of a container. Preferably, the defoamer is dimethyl polysiloxane emulsion and present in an amount in the range from 0.01-0.50%, more preferably 0.20%.
The synergistic fungicidal composition may contain a biocide selected from the group consisting of Proxel GXL, formaldehyde and combinations thereof, and present in an amount in the range from 0.01-0.50%, preferably 0.20%. Proxel GXL is a broad spectrum biocide for the preservation of industrial water-based products, such as the composition of the present invention, against spoilage from bacteria, yeasts and fungi.
It is necessary to add a thickener to a fungicidal composition to reduce the tendency of the fungicidal composition to disperse when sprayed, and decrease the likelihood of it being rinsed off of the crops. The synergistic fungicidal composition comprises xanthan gum as thickener in an amount in the range from 0.10-0.50%, preferably 0.25%.
It has been surprisingly found that the synergistic fungicidal composition of present invention provides a wide spectrum control of fungal pests and diseases, delaying the emergence of the resistant strains of the fungal pests, and achieving effective and economical control of undesired fungal pests and diseases.
The embodiments of the present invention are more particularly described in the following examples that are intended as illustrations only, since numerous modifications and variations within the scope of the present invention will be apparent to those of skill in the art. Unless otherwise noted, all parts, percentages and ratios reported in the following examples are on a weight basis and all reagents used in the examples were obtained or are available from the chemical suppliers.
EXAMPLES
Examples 1 to 4:
The unit of each value below is “% w/w” i. e. the percentage by weight, relative to the weight of the total solution or composition unless otherwise specified. The compositions illustrated in Table 1 are formulated as a suspension concentrate (SC).
Table 1: Synergistic fungicidal compositions
Component Function Examples
1 2 3 4
Thifluzamide A.I. 4.00 6.00 9.00 10.00
Difenoconazole A.I. 8.00 6.00 6.00 4.00
Validamycin A.I. 3.00 3.00 3.00 3.00
Propylene glycol Anti-freezing agent 5.00 5.00 5.00 5.00
Mixture of nonionic surfactants & amine salt of phosphate tristyryl phenol ethylated Dispersing cum wetting agent 5.00 5.00 5.00 5.00
Dimethyl Polysiloxane emulsion Defoamer 0.20 0.20 0.20 0.20
Proxel GXL Biocide 0.20 0.20 0.20 0.20
Xanthan Gum Thickener 0.25 0.25 0.25 0.25
Demineralized Water Solvent Q.S. Q.S. Q.S. Q.S.
A.I.= active ingredient
Q.S.= quantity sufficient
The aforementioned fungicidal mixtures can be formulated as suspension concentrate (SC) by the process described below.

Process for preparing synergistic fungicidal composition in the form of suspension concentrate (SC):
The novel fungicidal compositions of examples 1 to 4 are prepared by the process described hereinafter and in figure 1. The process for manufacture of 100 kg batch size of fungicidal composition comprising Thifluzamide, Difenoconazole and Validamycin is provided.
All the raw materials were verified for conformance to the laid down individual specifications. The raw materials required for preparing compositions of examples 1, 2, 3 and 4 are illustrated in table 2 under the column headings 1, 2, 3 and 4 respectively. Entries for Thifluzamide, Difenoconazole, and Validamycin in table 2 differ from those in table 1 as entries in table 1 are for 100% pure compounds, whereas those in table 2 are for technical ones, i.e. those containing a certain percentage of impurities.
The amounts of active ingredients presented in table 2 may be greater than the values calculated taking into account the percentage purity of the active ingredients, to compensate for losses of said ingredients during the manufacturing process. It was observed that following said procedure on industrial scale the final yield of A.I. will be similar or same as to standardized values.
The required quantities of raw materials as illustrated in Table 2 below are weighed and transferred through the auto-batching system. 40.00 kg of water is placed in a high speed homogenizer (2000 RPM) reactor with a cooling jacket. To this reactor, 5.00 kg of propylene glycol is added with slow stirring at approximately 80 RPM. To the resulting solution, 5.00 kg of combination of nonionic surfactants & amine salt of phosphate tristyryl phenol ethylated is added with slow stirring at approximately 80 RPM followed by addition of 100 g of defoamer with slow stirring. Thereafter, required quantity of thifluzamide technical and difenoconazole technical is slowly added with stirring at 2000 RPM. To the resulting solution, required quantity of validamycin technical is slowly added with stirring at 2000 RPM. The entire mixture is mixed well at 2000 RPM for 2 hours followed by cooling to 15°C.
After cooling, the above mixture is milled with bead mill to get particle size of 3-5 microns. The product, thus, obtained is transferred to another vessel having rotation speed of 60-80 RPM. Balance 100 g defoamer, biocide and 2% aqueous xanthan gum solution are added. Water is added to make up to 100 kg.
Thereafter, the batch is checked for quality parameters for conformity to laid down specifications and the material is packed as per requirement after quality approval.
Table 2: Quantities of the *TGAI and raw materials charged
Component Function Quantities of materials charged (kg)
1 2 3 4
Thifluzamide (based on 95% w/w minimum purity) *TGAI 4.22 6.32 9.48 10.53
Difenoconazole (based on 95% w/w minimum purity) *TGAI 8.43 6.32 6.32 4.22
Validamycin (based on 64% w/w minimum purity) *TGAI 4.70 4.70 4.70 4.70
Propylene glycol Anti-freezing Agent 5.00 5.00 5.00 5.00
Mixture of nonionic surfactants & amine salt of phosphate tristyryl phenol ethylated Dispersing cum wetting agent 5.00 5.00 5.00 5.00
Dimethyl Polysiloxane emulsion Defoamer 0.20 0.20 0.20 0.20
Proxel GXL Biocide 0.20 0.20 0.20 0.20
Xanthan Gum Thickener 0.25 0.25 0.25 0.25
Demineralized Water Solvent 72.00 72.01 68.85 69.90
*Technical grade active ingredient
Bio-efficacy of synergistic fungicidal composition against fungi in paddy crop
The field trials were conducted on paddy to evaluate the fungicidal control of major diseases with Thifluzamid, Difenoconazole and Validamycin alone and in ternary mixture, as a foliar application. The ternary mixture was prepared by the process described above. Commercially available compositions of Thifluzamide 24% SC (PULSER), Difenoconazole 25% EC (WILCORE) and Validamycin 3% L (WILPOWER) were diluted with water to the stated concentration of the active compound. Applications were made with a backpack type sprayer fitted with a pressure regulator and a vertical bar with one hollow cone nozzle. The application was initiated immediately after disease incidence and three directed sprays, i.e. 1st, 2nd and 3rd sprays or applications were made at intervals of 15 days. Experimental design was in random blocks with four repetitions, and each plot measured 50 sq. m. The dilution rate of application was 500 L/ha for all the trials. The percentage disease Index (PDI) per hill on ten hills per plot was assessed 10 days after application (DAA). The disease ratings are provided in table 3.
Per cent disease index (PDI) was calculated by using formula adopted by Horsfall and Heuberger (Horsfall. J.G and J.W. Henberger. 1942. Measuring magnitude of defoliation disease of tomatoes. Phytopath., 32: 226-232) as follows:
The per cent disease index (PDI) was calculated by using the following formula,
PDI = Sum of all disease Ratings______________ × 100
Total no of plants assessed x Maximum Disease rating

Table 3. Scale for measurement of disease intensity or disease rating
Grade Disease symptoms
0 No plants showing disease symptoms
1 1% or less plants showing disease symptoms
3 1-10% or less plants showing disease symptoms
5 11-20% or less plants showing disease symptoms
7 21-50% or less plants showing disease symptoms
9 51% and above plants showing disease symptoms

Using the above process, Thifluzamide, Difenoconazole and Validamycin were evaluated alone and in combination at different doses. Table 4 below summarizes the individual and combined treatments for disease spectrum at different concentrations of Thifluzamide, Difenoconazole and Validamycin.

Table 4. Treatment details for evaluation of bio-efficacy of synergistic fungicidal mixture against fungi on paddy crop
No. Treatment A.I. (%) Dose A.I./acre (g/acre) Volume of formulation (mL/ha)
T1 Thifluzamide + Difenoconazole + Validamycin 9% + 6% + 3% 72 + 48 + 24 800
T2 9% + 6% + 3% 90 + 60 + 30 1000
T3 9% + 6% + 3% 108 + 72 + 36 1200
T4 9% + 6% + 3% 126 + 84 + 42 1400
T5 Thifluzamide (PULSER) 24% 90 375
T6 Difenoconazole (WILCORE) 25% 62.5 250
T7 Validamycin (WILPOWER) 3% 60 2000
T8 Control (Water Spray) -- -- --
A.I.= active ingredient
The bio-efficacy of different treatment schedules on paddy crop and the treatment wise yield data of paddy crop are summarized in Tables 5 and 6 below.

Table 5: Effectiveness of fungicidal treatments on disease spectrum in paddy crop demonstrating the synergistic effect of novel fungicidal composition of Thifluzamide, Difenoconazole and Validamycin.

Treatments Volume (mL) PDI (%) Blast
(Leaf and Neck) PDI (%) Leaf Spot
(Brown Leaf Spot) PDI (%) Blight
(Becterial Leaf blight/Sheath Blight)
Mean after 1st spray Mean after 2nd spray Mean after 3rd spray Mean after 1st spray Mean after 2nd spray Mean after 3rd spray Mean after 1st spray Mean after 2nd spray Mean after 3rd spray
T1 800 04.2
(11.8) 6.8
(15.1) 8.5
(17.0) 9.5
(17.9) 15.8
(23.6) 20.2
(26.7) 12.6
(21.1) 16.5
(24.0) 22.5
(28.5)
T2 1000 03.4
(10.6) 5.2
(13.2) 7.5
(15.9) 8.6
(17.1) 12.2
(20.4) 17.4
(24.6) 9.3
(18.1) 15.3
(23.1) 19.8
(26.6 )
T3 1200 03.1
(10.1) 6.3
(14.5) 7.2
(15.6) 8.0
(16.4) 11.2
(19.6) 15.9
(23.) 6.2
(15.8) 13.2
(21.3) 19.3 (26.4)
T4 1400 03.1
(10.1) 5.8
(13.9) 6.8
(15.1) 8.0
(16.4) 10.4
(18.9) 15.8
(23.6) 4.8
(13.1) 11.1
(19.5) 17.7 (25.1)
T5 375 6.7
(15.1) 10.2
(18.6) 13.1
(21.2) 16.55
(24.02) 18.2
(25.3) 30.2
(33.5) 28.3
(32.20) 38.2
(38.2) 42.1
(40.4)
T6 250 7.7
(16.2) 11.9
(20.2) 12.8
(20.9) 14.2
(22.5) 17.2
(24.2) 28.8
(32.5) 20.2
(26.6) 25.8 (30.7) 38.2 (38.2)
T7 2000 14.5
(22.4) 22.5
(28.3) 25.9
(30.5) 17.7
(24.9) 25.2
(30.0) 40.1
(38.3) 11.3
(19.9) 15.3
(23.1) 20.4
(26.8)
T8 18.9
(25.8) 23.6
(29.9 ) 30.5
(33.5) 15.5
(23.2) 38.8
(38.5) 55.5
(48.2) 55.5
(48.2) 68.5
(55.9) 82.5
(65.3)
CD @ 5%$ - 0.45 0.55 0.46 0.56 0.42 0.64 0.92 1.12 1.11
SEm ± - 1.35 1.64 1.41 1.69 1.27 1.94 2.76 3.36 3.32
CD 5%: Critical Difference, m2 = Square meter; mL = Millilitre, Figures in parenthesis indicate arcsine transformed values.

The yield of paddy grains is summarized in table 6. The sun dried grains obtained after threshing and cleaning from the harvested area of each plot were weighed for recording yield in each plot. The yield thus obtained was then converted into quintal per hactare for each plot.
Table 6: Treatment wise yield data in paddy crop
Treatment Grain yield
(q/ha)
T1 36.80
T2 39.00
T3 39.61
T4 39.86
T5 33.46
T6 34.88
T7 30.96
T8 24.35
SEm+ 0.310
CD 5% 0.940
CD 5%: Critical Difference, q/ha = quintal per hectare
The aforementioned trial results indicate that the composition of present invention comprising Thifluzamide (9%), Difenoconazole (6.00%), and Validamycin (3.00%) formulated as a suspension concentrate (T4) is most effective against all the target fungi and affords the best yield.

Phytotoxic effect of synergistic fungicidal composition on paddy crop
Visual observation on phytotoxicity were recorded for leaf injury on tip/surface, Epinasty/Hyponasty, and wilting, etc. on 0-10 scale (table 7) at 1, 3, 7, 14 and 21 days after each application and the average values are presented in table 8.
Table 7. Phytotoxicity visual scoring 0 to 10
Score Phytotoxicity (percent)
0 No phytotoxicity
1 1 – 10
2 11 – 20
3 21 – 30
4 31 – 40
5 41 – 50
6 51 – 60
7 61 – 70
8 71 – 80
9 & 10 Complete destruction
Table 8: Phytotoxicity of different treatments on paddy crop
No. Treatments Dose (mL/ha) Phytotoxicity (Days after Application)
1 3 7 14 21
1 Thifluzamide 9% + Difenoconazole 6.00% + Validamycin 3.00% SC 1000 0 0 0 0 0
2 2000 0 0 0 0 0
3 4000 0 0 0 0 0
4 Control - 0 0 0 0 0
0= No Phytoxicity
The data presented in Table 8 shows that the synergistic fungicidal mixture comprising Thifluzamide, Difenoconazole and Validamycin did not show any phytotoxicity when applied at higher dose of 4000 mL/ha in paddy crop.
From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitations with respect to the specific embodiments illustrated is intended or should be inferred. It should be understood that all such modifications and improvements have been deleted herein for the sake of conciseness and readability but are properly within the scope of the following claims.

CLAIMS:
We claim:
1. A synergistic fungicidal composition, comprising Thifluzamide, Difenoconazole, Validamycin, and additives.
2. The synergistic fungicidal composition, as claimed in claim 1, wherein the mass ratio between Thifluzamide, Difenoconazole, and Validamycin ranges from 1.33-3.33:1.33-2.67:1, and is preferably 3:2:1.
3. The synergistic fungicidal composition, as claimed in claims 1 and 2, wherein Thifluzamide is present in an amount of 4 to 10%, Difenoconazole is present in an amount of 4 to 8% and Validamycin is present in an amount of 3%.
4. The synergistic fungicidal composition, as claimed in claims 1 to 3, wherein the composition is in the form of a wettable powder (WP), a suspension concentrate (SC), soluble liquid (SL) or water dispersible granules (WG).
5. The synergistic fungicidal composition, as claimed in claims 1 to 4, wherein the additives are selected from the group consisting of anti-freezing agent, dispersing cum wetting agent, defoamer, biocide, thickener, water and combinations thereof, and the composition is in the form of a suspension concentrate (SC).
6. The synergistic fungicidal composition, as claimed in claim 5, wherein the the anti-freezing agent is selected from the group consisting of propylene glycol, di-ethylene glycol (DEG), mono-ethylene glycol (MEG) and combinations thereof, and present in an amount in the range from 1.00 to 8.00%, preferably 5%.
7. The synergistic fungicidal composition, as claimed in claim 5, wherein the dispersing cum wetting agent is selected from the group consisting of mixture of non-ionic surfactants and amine salt of phosphate tristyryl phenol ethylated, acrylic copolymer, ethoxylated polyarylphenol phosphate ester and combinations thereof, and present in an amount in the range from 2.00 to 10.00%, preferably 5%.
8. The synergistic fungicidal composition, as claimed in claim 5, wherein the defoamer or anti-foaming agent is dimethyl polysiloxane emulsion and present in an amount in the range from 0.01 to 0.50%, preferably 0.20%.
9. The synergistic fungicidal composition, as claimed in claim 5, wherein the biocide is selected from Proxel GXL or formaldehyde and present in an amount in the range from 0.01 to 0.50%, preferably 0.20%.
10. The synergistic fungicidal composition, as claimed in claim 5, wherein the thickener is Xanthan gum and present in an amount in the range from 0.10-0.50%, preferably 0.25%.
11. The synergistic fungicidal composition as claimed in any of the claims 1 to 10, wherein said composition is non-phytotoxic.